From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752473AbaEABSV (ORCPT ); Wed, 30 Apr 2014 21:18:21 -0400 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:53352 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751016AbaEABSU (ORCPT ); Wed, 30 Apr 2014 21:18:20 -0400 Date: Wed, 30 Apr 2014 18:18:11 -0700 From: Mark Brown To: Maxime Ripard Cc: linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, Alexandre Belloni Message-ID: <20140501011811.GF3245@sirena.org.uk> References: <1398705774-12361-1-git-send-email-maxime.ripard@free-electrons.com> <20140429183758.GH15125@sirena.org.uk> <20140430180609.GC3000@lukather> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="SxgehGEc6vB0cZwN" Content-Disposition: inline In-Reply-To: <20140430180609.GC3000@lukather> X-Cookie: Keep it short for pithy sake. User-Agent: Mutt/1.5.23 (2014-03-12) X-SA-Exim-Connect-IP: 12.104.145.3 X-SA-Exim-Mail-From: broonie@sirena.org.uk Subject: Re: [PATCH] spi: Force the registration of the spidev devices X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: Yes (on mezzanine.sirena.org.uk) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --SxgehGEc6vB0cZwN Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Apr 30, 2014 at 11:06:09AM -0700, Maxime Ripard wrote: > On Tue, Apr 29, 2014 at 11:37:58AM -0700, Mark Brown wrote: > > Why can we not handle this by using sysfs to bind spidev to the > > device? > I just tried it, and apparently, you can't really use this, since spi > devices are created from the device tree (or ACPI) whenever the master > registers. Can you be more specific as to what the issue is here? If we actually have a specific kernel driver for a device I would strongly expect that we would want to use it and not spidev, if we don't have one I don't see the issue. > It doesn't really work either for a device that would be bound to a > driver, that you unbind, and then try to bind to spidev instead. It > looks like the device is released whenever you unbind it, so you can't > really use it afterwards. I guess this is the issue... what exactly is the use case here? I would only expect spidev to be used if there is no in kernel driver for a device. --SxgehGEc6vB0cZwN Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQIcBAEBAgAGBQJTYaDLAAoJELSic+t+oim9RtMP/R8l2pDy3bqibqmHefkf49sM hAPUtyVAW8E7b9ZafpJBwSov5k7zhsIk9mMqVLGtYQ2FH4TDc6mOTqfC9c5ykynu gHWvbMifqZbFfIk+kARGw93ezt403DpM/N1nzOdoqyk7QL83r7AjhtWYCyaYmGxi ORqpGkC787ppKZYdG0SdO8+SVem9esBGPf9fwwWlnfQAa6uH60k0U/3UkyRgm892 U0tuEpi5/Es19IfZdGIdKwP3x9yBzTe5yKGMjvXX/1oEtXrCKAp1UMgZzyXwmlwV gzS7S3FgdoPB512AV8d/FllXaU7BbCTjORxa1P018lq3YPL2e1cHeOBcqIQf4nQL rsSantc1xety9avVtVeDyiQqclnuMLr+4t/xJ4Lt50P+N+lCms1kUGWRg+4TmMzT xJ0n6cA3Zkso4rcCECSL1I4uC2uSHH2yZ4O+DZowZ2oV1nnj7E9wI2fyF+bH8Ha7 miEGewzxYfGF/wR0IVhHaTveOKH6XImFN5/pFYL6lJdk8ASARVI1JPRWIxeV0JEi 2q06gUmy3JT19fELJUMsZxEFCPkxjaC7B8GSE3ij78DlzbaswEOvT0An5ULTxptP jkvxr2xWacn5yI8M/ttJqPrv0hHB2P+sdXbBRsS1b9pLI8sLMqVby7w2rgl3TSU7 ADYu6PDek4BqTJwXQA9U =4Smf -----END PGP SIGNATURE----- --SxgehGEc6vB0cZwN--